For some people, glasses are indispensable. They have to wear them almost every second of their waking hours. Even for those who do not wear prescription glasses, if they like to be in the sun, sunglasses are essential. In other words, many of us constantly carry at least one pair of glasses with us.
Many of us also have to regularly wear or carry a watch or other electrical devices. Some people are already burdened by carrying too many separate devices and it can be expensive and inconvenient when a device is lost or forgotten.
Another interesting aspect in the glasses industry is that once you have bought a pair of glasses, they cannot be altered. Some of these glasses can be quite expensive, particularly those with a famous brand name. After-market enhancements or modifications to a pair of glasses are not readily available.
It should also be apparent from the foregoing that there is a continuing need to reduce the number of separate components or gadgets one tends to carry, and there is also a need to facilitate after-market enhancements or modifications for a pair of glasses.